摘要
由于小电流接地系统单相接地故障的故障电流小、故障过程持续时间短，且影响故障选线准确率因素多，采用常规的故障选线方法其准确率较低而采用暂态零序电流小波变换方法是目前研究的热点，可实现故障选线的准确性。为研究此一技术，在分析单相接地故障暂态电流特征的基础上，根据暂态电流行波幅值比较式方向保护选线原理，在MATLABSIMULINK平台上建立了不同馈线10kV配电网络的模型，利用Haar小波分析方法对2～30回馈线的10kV配电网络进行了仿真分析。结果表明，Haar小波可实现单相接地故障准确选线的目的，故障选线结果与配网的馈线数无关，选线的准确性与小波窗时间宽度有关，因此采用Haar小波进行故障选线时应根据系统的接地方式和配网的馈线数量合理调整小波窗时间宽度。
When a one-phase-to-ground fault of an indirectly grounding 10 kV power system occurs, the fault current is small and the fault duration is short. Furthermore, because many other factors influence the accuracy of the fault detection, the common methods of the fault location have low accuracy. The wavelet transform analysis based on the transient zero-sequence current that could increase the accuracy of the fault location is investigated. On the basis of the transient current characteristic analysis of one-phase-to- ground fault and according to the fault location principle of the transient current traveling wave amplitude comparison director protection, we established multi-feeder 10 kV power system models on MATLAB SIMULINK, and simulated from two up to thirty feeders with Haar wavelet. The simulation shows that Haar wavelet could locate the earthed fault feeder effectively. The results indicate that the feeder numbers have little influence on the fault detection, and the accuracy of the fault location is determined by the width of the wavelet time-window. Therefore, when the Haar wavelet is used for the earthed fault detection, the width of the wavelet time-window should be adjusted effectively according the grouding patterns of the neutral point and the feeder number of the power system.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2009年第12期3000-3006,共7页
High Voltage Engineering
关键词
馈线数
HAAR小波
故障
选线
小电流单相接地
10KV配电系统
feeder numbers
Haar wavelet
fault
location
small current single-phase-grounded
10 kV distribution system
